A 40-year-old man presents with a complaint of intermittent burning on his feet. He notes that the condition has waxed and waned in intensity over the past 3 years and only occurs in colder months, often after skiing or other outdoor activities. He has no history of systemic disease, denies recreational drug use, and does not smoke. He is current with COVID-19 immunizations and was diagnosed with a mild case of the disease ~8 months ago. His feet show no abnormalities at this visit but he has photos of the condition taken during a recent ski trip.
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Pernio, otherwise known as chilblains, is a benign vasospastic skin disorder affecting the acral skin areas, such as palms, soles, fingers, and toes.1 Pernio manifests after exposure to cold temperatures and dampness and is subdivided into primary and secondary forms. The primary form is idiopathic and not caused by underlying disease. Secondary forms accompany systemic lupus erythematosus or other pathologic processes such as cryoglobulinemia and monoclonal gammopathy.2
Pernio manifests as painful or mildly pruritic red-to-purple edematous papules and patches located on the acral surfaces of the fingers and toes. The disorder characteristically begins in early winter and often resolves by spring. Patients frequently develop recurrences during subsequent winters or following exposure to cold.
Although benign and self-limiting, pernio may mimic other vascular diseases such as thromboemboli and vasculitis, which can trigger an extensive workup.3 Transient vasospasm plays a role in its pathogenesis.4 COVID toes is a unique phenomenon linked to SARS-CoV-2 infection that manifests as chilblain-like eruptions on the feet.5
Pernio is best prevented by avoidance of cold exposure. Calcium channel blockers such as nifedipine are used to prevent recurrence and help promote faster healing.
Stephen Schleicher, MD, is director of the DermDox Dermatology Centers in Pennsylvania, associate professor of medicine at Geisinger Commonwealth Medical College, and clinical instructor of dermatology at Arcadia University and Kings College.
1. Nyssen A, Benhadou F, Magnée M, André J, Koopmansch C, Wautrecht JC. Chilblains. Vasa. 2020;49(2):133-140. doi:10.1024/0301-1526/a000838.
2. Gordon R, Arikian AM, Pakula AS. Chilblains in Southern California: two case reports and a review of the literature. J Med Case Rep. 2014;8:381. doi:10.1186/1752-1947-8-381
3. Prakash S, Weisman MH. Idiopathic chilblains. Am J Med. 2009;122(12):1152-1155. doi:10.1016/j.amjmed.2009.07.011
4. Shahi V, Wetter DA, Cappel JA, Davis MDP, Spittell PC. Vasospasm is a consistent finding in pernio (chilblains) and a possible clue to pathogenesis. Dermatology. 2015;231(3):274-279. doi:10.1159/000437224
5. Zaladonis A, Huang S, Hsu S. COVID toes or pernio? Clin Dermatol. 2020;38(6):764-767. doi:10.1016/j.clindermatol.2020.06.002